This is the Study Chair's grant proposal for the Convergence Insufficiency Treatment Trial (CITT). The CITT is a multi-center randomized clinical trial designed to compare the effectiveness of two active treatment approaches for children with symptomatic convergence insufficiency (CI). CI is a prevalent and distinct binocular vision disorder. Typical symptoms include double vision, eyestrain, headaches, and blurred vision while reading. It affects approximately 5% of children in the United States, and may have a serious impact on an individual's performance in school, choice of jobs, and quality of life. Clinical signs of CI include exophoria that is greater at near than at far, a receded near point of convergence, and reduced positive fusional vergence at near. [unreadable] [unreadable] There is no consensus regarding the most effective treatment for CI. Two commonly prescribed active treatments are Pencil Push-up therapy, which is the standard of care, and Vision Therapy/Orthoptics. Significant differences exist between these two treatment modalities in cost and number of office visits required, with Pencil Pushup therapy being less expensive and less time intensive. There have been no well-designed studies that compare the effectiveness of these two treatments. A randomized clinical trial is needed to evaluate the effectiveness of these treatments for CI. [unreadable] [unreadable] In the CITT, 208 patients between the ages of 9 and 18 years will be randomly assigned to: 1) office-based Vision Therapy/Orthoptics, 2) placebo office-based Vision Therapy/Orthoptics, 3) standard home-based Pencil Push-up therapy, and 4) office-based Pencil Push-up therapy. Measurements of the signs and symptoms of CI will be made at the eligibility examination and by masked examiners following every 4 weeks of treatment during the 12-week treatment phase. Patients who are successful after 12 weeks of treatment will be followed for 12 months to follow the long-term treatment effects. The primary outcome measure is the score on the Convergence Insufficiency Symptom Survey. [unreadable] Additional outcome measures include the near point of convergence and positive fusional vergence at near. This Study Chair grant proposal provides the rationale and design for the clinical trial. It includes the budget for the Study Chair's office, revised budgets for the clinical centers, the results of pilot studies funded by an NEI Clinical Trial Planning Grant, and the CITT Manual of Procedures. [unreadable] [unreadable] [unreadable]